23,910 research outputs found
Pairing properties of the inner crust of neutron stars at finite temperature
We investigate the thermal properties of the inner crust of a neutron star
using the Hartree-Fock-Bogoliubov (HFB) formalism at finite temperature. We
compare our results with the ones obtained solving the same equations, but
within the BCS approximation. We observe that for the outermost regions of the
inner crust, the two methods can show important differences, in particular when
we use them to calculate the neutron specific heat of the system
Generating functionals, consistency, and uniqueness in the integral equation theory of liquids
We discuss and illustrate through numerical examples the relations between
generating functionals, thermodynamic consistency (in particular the
virial-free energy one), and uniqueness of the solution, in the integral
equation theory of liquids. We propose a new approach for deriving closures
automatically satisfying such characteristics. Results from a first exploration
of this program are presented and discussed.Comment: 27 pages, 5 figure
Electromagnetic structure of light nuclei
The present understanding of nuclear electromagnetic properties including
electromagnetic moments, form factors and transitions in nuclei with A 10
is reviewed. Emphasis is on calculations based on nuclear Hamiltonians that
include two- and three-nucleon realistic potentials, along with one- and
two-body electromagnetic currents derived from a chiral effective field theory
with pions and nucleons.Comment: Invited talk at the 21st International Conference on Few-body
Problems in Physics, Chicago, IL, USA, May 18-22, 2015. 9 page
Pairing properties and specific heat of the inner crust of a neutron star
We investigate the pairing properties at finite temperature of the
Wigner-Seitz cells in the inner crust of a neutron star obtained with the
recent Brussels-Montreal Skyrme functional BSk21. In particular we analyze the
phenomena of persistence and reentrance of pairing correlations and their
impact on the specific heat in the low-density region of the inner crust.Comment: Submitted to Phys. Rev.
Overlapping: a R package for Estimating Overlapping in Empirical Distributions
overlapping is an R package for estimating the overlapping area of two or more kernel
density estimations from empirical data. The main idea of the package is to offer an
easy way to quantify the similarity (or the difference) between two or more empirical
distributions
Pairing in exotic neutron rich nuclei around the drip line and in the crust of neutron stars
Exotic and drip-line nuclei as well as nuclei immersed in a low density gas
of neutrons in the outer crust of neutron stars are systematically investigated
with respect to their neutron pairing properties. This is done using Skyrme
density-functional and different pairing forces such as a density-dependent
contact interaction and a separable form of a finite-range Gogny interaction.
Hartree-Fock-Bogoliubov and BCS theories are compared. It is found that neutron
pairing is reduced towards the drip line while overcast by strong shell
effects. Furthermore resonances in the continuum can have an important effect
counterbalancing the tendency of reduction and leading to a persistence of
pairing at the drip line. It is also shown that in these systems the difference
between HFB and BCS approaches can be qualitatively large
Tailored material properties using textile composites
Lightweighting is essential for the reduction of energy consumption in transportation. The most common approach is through the application of high specific strength and stiffness materials, such as composites and high performance aluminum alloys. One of the challenges associated with the use of advanced materials is the high cost. This paper explores the opportunities of using hybrid composites (glass and carbon, for example) with selective fiber placement to optimize the weight subject to price constraints for given components.
Considering the example of a hat-section for hood reinforcement, different material configurations were modeled and developed. The required thickness of the hat section to meet the same bending stiffness as an all carbon composite beam was calculated. It was shown that selective placement of fiber around the highest moments results in a weight savings of around 14% compared to a uniformly blended hybrid with the same total material configuration. From this it is possible to estimate the materials cost of the configurations as well as the weight of the component. To determine which is best it is necessary to find an exchange constant that converts weight into cost – the penalty of carrying the extra weight. The value of this exchange constant will depend on the particular application
School-to-Work Transitions in Mongolia
Relatively little is known about the youth labour market in Mongolia. This paper addresses the issue by taking advantage of a recent ad hoc School to Work Transition Survey (SWTS) on young people aged 15-29 years carried out in 2006. After a period of sharp reduction in the 1990s, educational attainment is increasing, as compared to other countries in the area. Nonetheless, important constraints seem to affect the supply of education, especially in rural areas. In addition, as application of the new ILO school-to-work transition classification shows, the country is unable to provide young people with a sufficient number of decent jobs. This translates into high youth unemployment in urban areas and very low productivity jobs in rural areas. Mincerian estimates confirm that human capital is an important determinant of earnings in urban, but not in rural areas.Economic Transition from Plan to Market; School to Work Transitions; Youth Labour Supply and Demand; Earnings; Gender Pay Gap; Urban/Rural Divide; Mongolia
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